MEASUREMENT METHOD OF SYNCHROPHASOR OF OPERATING CONDITION OF POWER SYSTEM, AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2014 - IPC G01R23/02 

FIELD: measurement equipment.

SUBSTANCE: current frequency of a power system is determined as per sampling of digitised values of an operating condition. Parameters of a synchrophasor of the operating condition are determined as per parameters of a pair of vectors. Parameters of vectors are calculated by means of a discrete Fourier transformation method. Calculation of one of the vectors is made using the frequency equal to the whole part of the current frequency value of the power system, and the other one - using frequency that is higher by 1 Hz and using cosine and sine harmonic functions with these frequencies. A phase of these functions is calculated starting from the moment of the last 1PPS. A synchrophasor module is determined by means of linear interpolation as per frequency of modules of the above vectors, and an angle is determined by linear interpolation of angles of vectors and by adding to the obtained values of difference of current and nominal frequencies of the power system, which is multiplied by 2π and by time interval that passed from the time mark of the synchrophasor to the last second mark, 1PPS. A device for implementation of the above method is proposed. The device includes an analogue signal input unit, a receiving unit of signals of the common-timing system, an analogue-to-digital converter (ADC), a discretisation synchronising pulse oscillator, two generation units of cosine signals, two calculation units of vectors of the operating condition, a transfer unit of measurement results to a data gathering centre, as well as a measurement unit of current frequency of the power system, a frequency interval calculation unit and a vector parameter interpolation unit.

EFFECT: improving accurate measurement of operating conditions in a wide range of variation of current frequency of a power system.

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